the Pentagon, the largest office building in the world, completed in just 16 months of frantic wartime labor, 83 years ago

 

On this day, 83 years ago, January 15, 1943, Secretary of War Henry L. Stimson stood before thousands on a frigid Virginia morning to dedicate the Pentagon, the largest office building in the world, completed in just 16 months of frantic wartime labor.

Ground had broken on September 11, 1941, on the former Hoover Field airport site in Arlington County across the Potomac from Washington, D.C., after President Roosevelt approved the location to avoid blocking views from Arlington National Cemetery. Brigadier General Brehon Somervell drove the project forward, securing Congress approval in July 1941 amid the War Department's desperate need for centralized space as World War II loomed, with offices scattered across dozens of temporary buildings in D.C., Maryland and Virginia.

​

Contracts worth $31.1 million went to John McShain Inc. of Philadelphia, plus Virginia firms Wise Contracting and Doyle and Russell, on the same day groundbreaking started, with Colonel Leslie Groves overseeing for the Army Corps of Engineers.

Architect George Bergstrom designed the five-sided behemoth to fit the Pentagon shape of the Arlington Farms site initially considered, then adapted for the regular pentagon at Hoover Field, each facade 921 feet long, 77 feet high, spanning 29 acres with five concentric rings labeled A to E and corridors totaling 17.5 miles.

To save steel for the war effort, crews poured reinforced concrete using 680,000 tons of Potomac River sand, built concrete ramps instead of elevators, skipped bronze doors and copper trim, and dredged a lagoon under the river entrance.

​

Laborers worked three shifts around the clock, 4,000 men at peak by December 1941 when President Roosevelt signed over military construction to the Corps of Engineers, pouring foundations on floodplain soil with cast-in-place piles and retaining walls to handle 10-to-40-foot elevation shifts.

​

By 1943 occupancy, 23,000 military and civilian staff worked there, plus 3,000 support personnel, navigating rings via numbered corridors from the courtyard, reaching any point in under ten minutes. The Pentagon centralized command as the U.S. mobilized millions, its five facades facing Mall Terrace north, River Terrace northeast over the lagoon, Concourse southeast with Metro and bus access, South Parking southwest, and Army Heliport west along Washington Boulevard. Post-war, it became Department of Defense headquarters, enduring a 1998-2011 gut renovation removing asbestos, sealing windows and standardizing open bays with modern HVAC.

#OnThisDay #Pentagon #ThenAndNow